You isolate ten new mutant yeast strains that are defective in synthesis of leucine, an amino  acid. These Leu- mutants (numbered 1-10) were all isolated in a strain of mating type a (MAT a).  S. cerevisiae yeast are either mating type a or α. As it turns out, your high school classmate,  now at the University of Chicago, has independently isolated ten yeast Leu- mutants (numbered  11-20) in a strain of mating type α (MAT α). You and your ex-classmate decide to combine your  resources and determine how many different genes are represented by your 20 mutant strains.  You cross each of the MAT a strains to each of the MAT α strains. Your experimental  observations are shown in the table below, where an empty square indicates that the diploid did  not grow on minimal medium and a filled square indicates that the diploid did grow on minimal  medium.  Based on this experiment, what is the minimum number of genes required for leucine  synthesis?

PLEASE ANSWER BOTH PARTS OF THE QUESTION a.) The Question on the image b.) From this experiment, in how many genes have we identified mutations?

5- ddNTP differs from dNTP in..... and N is representing.. a) The first has no OH in both C 1,2, but dNTP has OH in C3 of the sugar/A, G.T.C. b) The first has no OH in both C 2 & 3, but dNTP has OH in C3 of the sugar/the bases. c) ddNTP is used to stop DNA elongation / nitrogen d) ddNTP has only one OH in C3/A,G,T.,C

Why bacteriophage is called t4?

35. M Heinz Shuster collected the following data on the base composition Move ANALYSIS ribgrass mosaic virus (H. Shuster, in The Nucleic Acids: Chemistry and Biology, vol. 3, E. Chargaff and J. N. Davidson, Eds. New York: Academic Press, 1955). On the basis of this information, is the hereditary information of the ribgrass mosaic virus RNA or DNA? Is it likely to be single stranded or double stranded? Percentage A T U Ribgrass 29.3 25.8 18.0 0.0 27.0 mosaic virus Leibniz Institute for Age Research, Fritz Lipmann-Institute. Ribgrass mosaic virus.

So if you see growth on a histidine-deficient medium in a yeast 1 hybrid and you assume that it is a false positive. What could have caused this? The yeast cells are normal and this wasn't caused by other molecules.

What is the correct answer, and why?

Second, Question 2

O All bacteria are naturally competent to undergo transformation under any condition. O A bacteria can only take up DNA from another living cell during transformation. Question 30 Which of these is NOT a correct statement about bacterial conjugation? O An F+ cell makes sex pili and attaches to an F- cell. O After conjugation between an Hfr and F- cell, the F- cell has a change in its chromosomal DNA O After conjugation between an F+ and F- cell, the F- cell has become F+. O After conjugation between an F+ and F- cell, the F+ cell has become F-. Question 31

In transformation, a bacterial cell takes up DNA fragments from its surroundings. The figure shows the process of natural transformation. Position the labels below with the correct images. (A) Donor and recipient genomes The donor strand is integrated into the recipient chromosome and the displaced bacterial DNA is degraded. A wild-type donor cell is in the vicinity of a double auxotroph. If the wild-type cell lyses, it releases DNA into the environment. One cell is identical to the original recipient, while the other carries the wild-type genes. A competent recipient cells a receptor site on its surface. One strand of donor DNA enters the cell and pairs with a homologous region of the bacterial chromosome The remaining DNA strand is degraded. A donor DNA strand binds to the receptor site. Reset trpC1 Wild-type donor cell Mechanism of natural transformation Donor DNA hal Receptor site- trpc/his double auxotroph Recipient cell Competent cell recipient -Bacterial chromosome (had.bpC") Ma…